水稻纹枯病始发期和病情关键影响因子研究

为明确黑龙江省水稻纹枯病的始发期和病情扩展蔓延关键影响因子,利用4 a的纹枯病病情田间调查数据和气象数据,确定水稻孕穗期是纹枯病的始发期,使用SPSS软件分析结果表明,夜间大气温度是影响黑龙江省纹枯病病情的关键因子。     

水稻纹枯病对水稻产量的影响

田间试验研究了不同水稻品种对水稻纹枯病发病程度和产量的影响。结果表明,水稻纹枯病属中等偏重发生,对产量影响大,空育131病情指数最高,为26.15,产量损失最高,为28.29％。     

水稻纹枯病的发生原因及防控技术

近十几年来,清流县水稻纹枯病逐年发生日趋严重,此病害发病初期常被忽略,后期严重影响粮食产量。对清流县纹枯病发生、危害因素进行分析,并介绍有效的防控措施。     

拮抗细菌Bacillus subtilis B5423-R 抑制水稻纹枯病的阈值群体数量

 在菲律宾国际水稻研究所实验农场田间条件下，通过人工接种Rhizoctonia solani,采用不同的方法(喷雾次数、间隔期)喷雾B5423-R（B5423的标记菌株，为利福平Rifampicin抗性的突变体），在接种1 d后，采用2 d喷1次、连续3～4次喷雾的方法，使B5423 R在稻株上的群体数量在6～7 d内维持在1×10[sup]6[/sup]cfu/g以上，在25 d内显著地降低相对病斑高率；而采用5 d喷1次、连续3～4次喷雾的方法，B5423-R在稻株上的群体数量在15 d内维持在1×10[sup]5[/sup]～106cfu/g，在25 d内相对病斑高率未能显著降低。表明在纹枯病侵染早期的6～7 d内，在稻株上B5423 R维持在1×10[sup]6[/sup]cfu/g以上是抑制纹枯病的阈值群体数量。     

浦城县水稻纹枯病的发生与防控技术

水稻纹枯病是浦城县水稻主要病害之一,2011—2020年全县年均发生面积26153.3 hm2,防治面积23133.3 hm2,产量损失3626.3 t.通过对浦城县2011—2020年水稻纹枯病发生特点,开展相关防效试验,探索出推广使用抗(耐)性品种、机械插秧(宽行窄株)、测土配方施肥、打涝田间菌核、加强田间肥水管理...     

寒地水稻纹枯病的发生与防治

水稻纹枯病是一种水稻真菌性病害。目前其发生日渐普遍并且严重,给水稻生产造成很大损失。介绍了水稻纹枯病的发病症状、发病条件,从选用抗病品种、做好农业防治、加强栽培管理、适期药剂防治等方面提出了寒地水稻纹枯病的综合防治措施。     

氮肥运筹对水稻植株不同形态氮素含量的影响

以桂朝2号和叠加占为试验材料,以总氮、蛋白氮、叶绿素氮、可溶性蛋白氮、Rubisco-N、游离氨基态氮为指标,研究了氮肥运筹对水稻植株不同形态氮素含量的影响。结果表明,上述形态氮素含量对氮肥运筹表现出相同的趋势,即水稻抽穗期和成熟期植株总氮、蛋白氮、叶绿素氮、可溶性蛋白氮、Rubisco-N、游离氨基态氮含量均随施氮水平提高而提高,在相同施氮量条件下,重施穗肥时其含量较高。氮肥运筹对不同形态氮素含量的影响程度是不同的,其中,对Rubisco-N和游离氨基态氮的影响明显。两个品种早晚季无论是抽穗期还是成熟期不同施氮水平下Rubisco-N和游离氨基态氮含量差异均达到显著或极显著水平。相关分析表明,早晚季抽穗期和成熟期水稻植株总氮含量与蛋白氮含量均呈极显著相关。     

水稻纹枯病对水稻产量及米质的影响

水稻纹枯病是水稻的三大病害之一,由于水稻纹枯病只是一种隐性减产,并不被大多水稻生产者所重视,使该病目前危害程度愈来愈严重。本试验针对水稻纹枯病害对水稻产量及稻米品质的影响进行初步研究。探讨水稻纹枯病不同病害级别、不同病情指数对水稻产量和稻米品质的影响,得出水稻纹枯病不但影响水稻的产量,而且还严重影响水稻的稻米品质,以此引起水稻生产者对水稻纹枯病的重视。在生产上加强对水稻纹枯病的防治,确保水稻高产优质。     

水稻最适叶面积指数和总颖花数的品种差异

以淮北地区不同历史年代的水稻品种为试验材料,研究叶面积和颖花量与品种产量能力进展的关系。结果指出:随品种最适叶面积指数和适宜总颖花量的增加,水稻品种的产量能力明显提高。因此确认高产品种选育应以增加最适叶面积指数和颖花量并适当减少穗数,应用半矮秆基因为途径。本文根据试验资料提出了目前淮北主要水稻品种的适宜群体指标,为良种选育和高产栽培提供依据。     

水稻苗期纹枯病抗性鉴定微室接种技术的改良

水稻对纹枯病的抗性属于典型的数量性状,多数栽培品种的抗病水平较低,并且抗性差异较小。水稻纹枯病接种和抗性评价体系是培育抗病品种的重要基础。利用植物生长箱的控温、控光和控湿条件以及生长势相对一致的水稻秧苗,对苗期纹枯病微室接种技术进行了改进。试验品种苗期的纹枯病抗性从高到低依次为YSBR1、特青、泰粳394、日本晴和Lemont,并且与大田成株期接种鉴定的结果一致。RT-PCR分析显示,苗期和成株期接种纹枯病菌均诱导4个水稻抗病相关基因的表达。通过"叶枕高"和"苗挺高"计算的各品种苗期病级变幅分别为2.82~8.54级和1.20~3.39级。前者与大田成株期的病级变幅一致,因而"叶枕高"病级计算方法更适用于微室接种鉴定体系。     

Advances in Mapping Loci Conferring Resistance to Rice Sheath Blight and Mining Rhizoctonia solani Resistant Resources

Sheath blight (SB) caused by Rhizoctonia solani is one of the three major diseases of rice, and now has become the most severe disease causing rice yield loss in China. Breeding and use of varieties resistant to SB is crucial in controlling the disease, but the advances achieved have been limited due to the lack of highly SB-resistant rice germplasm. Genetic analysis revealed that the SB resistance in rice was a typical quantitative trait controlled by multi-genes. Although many QTLs conferring resistance t...     

Efficacy of Bacillus subtilis MBI 600 Against Sheath Blight Caused by Rhizoctonia solani and on Growth and Yield of Rice

Rice sheath blight disease(ShB),caused by Rhizoctonia solani,gives rise to significant grain yield losses.The present study evaluated the efficacy of Integral?,the commercial liquid formulation of Bacillus subtilis strain MBI 600,against rice ShB and for plant growth promotion.In greenhouse studies,four log concentrations of Integral(from 2.2×106 to 2.2×109 cfu/mL) were used as seed treatment(ST).After 25 d,seedlings were dipped(SD) into Integral prior to transplanting.At 30 d after transplanting(DAT),leaf sheaths were inoculated with immature sclerotia of the pathogen.At 45 DAT,a foliar spray(FS) with Integral was applied to some treatments.The fungicide control was 50% carbendazim at 1.0 g/L,and a nontreated control was also included.Overall,there were 10 treatments,each with five replications.ShB severity was rated at 52 DAT,and seedling height and number of tillers per plant were rated at 60 DAT.In 2009,two field trials evaluated Integral at 2.2×108 and 2.2×109 cfu/mL.Integral was applied as ST,and seedlings were produced in a nursery bed.After 32 d,seedlings were treated with Integral as SD and transplanted into 10 m2 blocks.Foliar sprays were given at 45 and 60 DAT.There were seven treatments,each with eight replications arranged as a factorial randomized complete block design.At 20 DAT,the plots were broadcast inoculated with R.solani produced on rice grains.Seedling height before transplanting,ShB severity at 90 DAT,and grain yield at harvest were recorded.Integral at 2.2×109 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions.The Integral treatments of ST + SD + FS at 2.2×109 cfu/mL significantly suppressed ShB over other treatments.In field studies,Integral provided significant increase of seedling height in nursery,and number of tillers per plant,compared with the control.ShB severity was significantly suppressed with higher concentrations of Integral compared to lower concentrations.Grain yield were the highest at an Integral concentration of 2.2×109 cfu/mL.Overall,Integral significantly reduced ShB severity,enhanced seedling growth,number of tillers per plant and grain yield as ST + SD + FS at the concentration of 2.2×109 cfu/mL under the conditions evaluated.     

Establishment of Agrobacterium tumefaciens-Mediated Transformation System for Rice Sheath Blight Pathogen Rhizoctonia solani AG-1IA

To construct the T-DNA insertional mutagenesis transformation system for rice sheath blight pathogen Rhizoctonia solani AG-1 IA,the virulent isolate GD118 of this pathogen was selected as an initial isolate for transformation.The conditions for transformation of isolate GD118 were optimized in five aspects,i.e.pre-induction time,co-culture time,acetosyringone(AS) concentration at the co-culture phase,co-culture temperature and pH value of induction solid medium(ISM) at the co-culture phase.Finally,a system ...     

18.7%丙环·嘧菌酯对水稻纹枯病的防治效果

2015年,在中国主要水稻种植区安徽、湖北、江苏、广东和广西等地进行18.7 %丙环·嘧菌酯的水稻纹枯病防治示范试验。结果表明,18.7 %丙环·嘧菌酯在600-750 mL/hm2使用剂量下,纹枯病发病初期(丛发病率达5 %左右)时用药1次,隔10 d再用药第2次,对纹枯病的防治效果突出,且显著优于对照,对水稻安全,具有明显的增产效果。     

盘锦水稻纹枯病发展趋势及防控技术

通过对盘锦稻区水稻纹枯病的发展趋势调查,明确了影响水稻纹枯病发生的相关因子及该病害对水稻产量的影响。结合盘锦地区的水稻生产情况提出了培育壮苗、加强田间管理、结合气候因子、药剂防治等对纹枯病的可持续防控技术。     

纹枯病菌对不同水稻品种叶片中抗病性相关酶活性的影响

对优质抗纹枯病水稻品种ZH5、较抗纹枯病品种特青、感纹枯病品种Lemont及恢复系泸恢17、多系1号和GB8等水稻材料进行纹枯病菌接种,测定了水稻叶片中与抗病性相关的超氧化物歧化酶 (SOD)、过氧化物酶 (POD) 的活性和丙二醛 (MDA) 的含量。不论纹枯病菌接种与否,ZH5和特青叶片中SOD活性均明显高于Lemont;纹枯病菌接种后,抗性品种ZH5和特青叶片中POD活性升高,感病品种Lemont 叶片中POD活性降低;不论是抗病还是感病的水稻材料,纹枯病菌接种后叶片中MDA含量均有所增加,但ZH5叶片中MDA含量明显低于其他参试材料。     

Gram-Positive Bacteria Associated with Rice in China and Their Antagonists Against the Pathogens of Sheath Blight and Bakanae Disease in Rice

Rice (Oryza sativa L.) is one of the most important crops, which feeds half of the population in the world. It’s the principle of the Integrated Pest Management (IPM) to maintain the pest damage under an economical permitted level by means of resistant cutivars and biological control. Some of the bacteria from rice plants are pathogenic [1], but most of them are nonpathogenic ones, which provide abundant resources for the biological control to rice diseases. It is a first key step of biolo…     

羧基化壳寡糖络合碘（CCOS-I）对水稻纹枯病菌的抑制作用及机理初讨

为明确羧基化壳寡糖络合碘（CCOS-I）对水稻纹枯病的防治作用,以 20%井冈霉素可湿性粉剂为对照药剂,测定 CCOS-I 对水稻纹枯病菌的室内抑菌效果和田间防效,以及对超氧化物歧化酶（superoxidedismutase,SOD）、叶片过氧化物酶（peroridase,POD）、多酚氧化酶（polyphenol oxidase,PPO）、苯丙氨酸解氨酶（phenylalanine ammonia-lyase,PAL）和 β-1,3-葡聚糖酶（β-1,3-glucanase）等相关防御酶活性的影响。结果表明：羧基化壳寡糖络合碘对该病菌抑制效果明显,经室内毒力测定,其 EC50 值 12.22 mg/L,明显高于对照药剂 20%井冈霉素粉剂。田间药效试验结果表明,在水稻第 3 次用药后 14 d,100 g/hm2 的羧基化壳寡糖络合碘防效达到 80.66%,与井冈霉素有效剂量 150 g/hm2 的效果相当,优于同剂量井冈霉素处理。CCOS-I 在试验剂量范围内对水稻纹枯病有很好的防治作用,且对水稻生长无任何药害现在发生,可以诱导水稻相关防御酶活性提高,适用于水稻纹枯病的防治,具有一定的开发推广价值。